Field
The embodiments disclosed herein relate to compression and retrieval of three-dimensional (3-D) laser scan data.
Relevant Technology
Scanning devices for capturing 3-D reality using laser imaging, detection, and ranging (LIDAR) techniques such as those described in U.S. Pat. No. 7,701,558 and U.S. Pat. No. 5,988,862 have been growing in popularity and usage. Generally, the laser scanners may include some form of LIDAR that generates one or more range samples of one or more target surfaces. The LIDAR may also generate ancillary data associated with the samples, such as a measure of the return intensity of the laser, described as “active color” and/or the color of the sampled surface described as “passive color.” Intensity may refer to the light returned from the surface from the laser, which may include several distinct wavelengths. Color may refer to light passively returned from a surface, which may be composed of one or more distinct bands of interest as with hyper spectral and/or thermal imaging.
The LIDAR may be mechanically positioned by the laser scanner to sample a region of interest over time. The mechanical positioning of the LIDAR is described as scanning. The positioning process may determine an origin and direction of the LIDAR sample. Together with the range(s), the origin and the direction may be employed to generate sample point(s) in a base coordinate system. Each sample point, together with its ancillary data such as return intensity and/or color, may be described as a scan point. A collection of scan points may be described as a scan. The scan may include scan lines, each of which may include a collection of scan points collected during a single mechanical motion or sweep.
Several examples of mechanical positioning exist. On a typical terrestrial survey LIDAR, such as a Leica ScanStation C10, the mechanical positioning of the LIDAR may be achieved by vertically deflecting a field of view of the LIDAR with a vertical deflector and horizontally rotating the vertical deflector together with the LIDAR. In this way, a scanning field of view generally resembling a sphere may be achieved. In some airborne LIDAR systems, such as the Leica ALS70, the LIDAR may be deflected across a flight path by a deflector. The deflector and the LIDAR may be mounted to an aircraft. Similarly, in some ground-vehicle-based LIDAR systems, the LIDAR may be deflected about an environment as the vehicle moves along a path. A targeting wedge prism scanner may form a LIDAR field of view by passing a laser beam through two round wedge prisms, one rotating at a much slower speed than the second, thus creating a spiral LIDAR sampling path.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.